Evaporated fuel treatment device for motorcycle

ABSTRACT

A charge pipe passage includes a first tank-side pipe passage part which is connected to an upper surface of a fuel tank, and a second tank-side pipe passage part which is connected with the first tank-side pipe passage part and extends toward the other side of the fuel tank from one side of the fuel tank in the vehicle widthwise direction on an end portion thereof on a fuel tank side, and the first and second tank-side pipe passage parts, are fixed to the upper surface of the fuel tank.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of priority to JapanesePatent Application No. 2011-063113, filed on Mar. 22, 2011, the entirecontent of which is incorporated by reference.

TECHNICAL FIELD

The present disclosure relates to a motorcycle which includes: an enginewhich generates power for driving a rear wheel; a fuel tank which storesfuel to be supplied to the engine; a fuel absorption means which isarranged below an upper surface of the fuel tank so as to absorb a fuelgas evaporated in the fuel tank outside the fuel tank; and a charge pipepassage which introduces a fuel gas to the fuel absorption means fromthe fuel tank, and more particularly to the improvement of an evaporatedfuel treatment device.

BACKGROUND OF THE INVENTION

There has been known a motorcycle which introduces a fuel gas generatedin a fuel tank into a canister arranged at an oblique frontward anddownward position from the fuel tank through a charge pipe passage inJapanese Patent No. 4108954.

SUMMARY OF THE INVENTION

However, in the motorcycle disclosed in Japanese Patent No. 4108954, thecharge pipe passage is connected to the canister only along a left sideof the motorcycle from an upper surface of the fuel tank and hence, whenthe motorcycle falls leftward, there exists a possibility that a largeamount of fuel flows out from the fuel tank toward a canister side.

The present disclosure has been made in view of the above-mentionedcircumstances, and it is an object of the present disclosure to providean evaporated fuel treatment device for a motorcycle which can suppressthe flowout of fuel from a fuel tank toward a fuel absorption means sidewhen the motorcycle falls.

To achieve the above-mentioned object, according to the first technicalfeature of the present disclosure, there is provided an evaporated fueltreatment device for a motorcycle which includes: an engine whichgenerates power for driving a rear wheel; a fuel tank which stores fuelto be supplied to the engine; a fuel absorption means which is arrangedbelow an upper surface of the fuel tank so as to absorb a fuel gasevaporated in the fuel tank outside the fuel tank; and a charge pipepassage which introduces a fuel gas to the fuel absorption means fromthe fuel tank, wherein the charge pipe passage includes a firsttank-side pipe passage part which is connected to the upper surface ofthe fuel tank, and a second tank-side pipe passage part which iscommunicably connected with the first tank-side pipe passage part andextends toward the other side of the fuel tank from one side of the fueltank in the vehicle widthwise direction on an end portion thereof on afuel tank side, and the first tank-side pipe passage part and the secondtank-side pipe passage part are fixed to the upper surface of the fueltank.

The present disclosure also has, in addition to the first technicalfeature, the second technical feature that the first tank-side pipepassage part extends toward the one side of the fuel tank from aconnection part connected to the upper surface of the fuel tank in thevehicle widthwise direction, and is communicably connected to the secondtank-side pipe passage part.

The present disclosure also has, in addition to the second technicalfeature, the third technical feature that a fuel filling port is formedin the upper surface of the fuel tank on the one side in the vehiclewidthwise direction, and the first tank-side pipe passage part which isconnected to the upper surface of the fuel tank at a position offsetfrom the fuel filling port and the second tank-side pipe passage partare communicably connected to each other in a state where the firsttank-side pipe passage part and the second tank-side pipe passage partsurround the periphery of the fuel filling port.

The present disclosure also has, in addition to the third technicalfeature, the fourth technical feature that a tray which receives fuelspilt from the fuel filling port is arranged around the fuel fillingport, and a part of the first tank-side pipe passage part and a part ofthe second tank-side pipe passage part are arranged to pass below thetray.

The present disclosure also has, in addition to any one of the first tofourth technical features, the fifth technical feature that the chargepipe passage includes a third tank-side pipe passage part which isconnected to the second tank-side pipe passage part on the other side inthe vehicle widthwise direction and has a highest part arranged at ahighest position of the charge pipe passage at an intermediated positionthereof.

The present disclosure also has, in addition to the fifth technicalfeature, the sixth technical feature that a part of the third tank-sidepipe passage part which includes at least the highest part is formed ofan elastic tube, and the highest part of the elastic tube is supportedon a highest part support part mounted on the fuel tank from below.

The present disclosure also has, in addition to the fifth or sixthtechnical feature, the seventh technical feature that a part of thecharge pipe passage ranging from the highest part to the connection partconnected to the fuel tank is arranged with a downward gradient towardthe connection part.

The present disclosure also has, in addition to any one of the fifth toseventh technical features, the eighth technical feature that the fuelabsorption means is a crankcase which stores oil for absorbing the fuelgas and constitutes a part of the engine, a downstream end of the chargepipe passage is connected to the crankcase in a state where thedownstream end of the charge pipe passage opens in the oil, and a firstcheck valve which prevents a backflow of a fuel gas toward the fuel tankis interposed on the charge pipe passage downstream of the highest partin a state where the first check valve is supported on the fuel tank.

The present disclosure also has, in addition to the eighth technicalfeature, the ninth technical feature that the upper surface of the fueltank includes a higher part in which the fuel filling port is formed anda lower part lower than the higher part, and the first check valve isarranged on the lower part.

The present disclosure also has, in addition to the ninth technicalfeature, the tenth technical feature that the lower part is formed in adownwardly inclined manner toward a crankcase side.

The present disclosure also has, in addition to any one of the eighth totenth technical features, the eleventh technical feature that anatmospheric air introducing pipe passage which introduces atmosphericair to the inside of the fuel tank is connected to a branch part whichis formed on the charge pipe passage at a position closer to the fueltank side than the first check valve, and a second check valve whichprevents the flow of a fuel gas from the fuel tank side is interposed onthe atmospheric air introducing pipe passage.

The present disclosure also has, in addition to any one of the first toeleventh technical features, the twelfth technical feature that a partof the elastic tube which constitutes at least a part of the charge pipepassage and is arranged above the fuel tank is held by an upper openclamper which is mounted on the upper surface of the fuel tank, and thefuel tank is covered with a tank cover which prevents the removal of theelastic tube from the upper open clamper from above.

The present disclosure also has, in addition to any one of the first totwelfth technical features, the thirteenth technical feature that painttreatment is applied to an outer surface of the fuel tank, and ametallic pipe which constitutes a part of the charge pipe passage isfastened to the fuel tank.

According to the first technical feature of the present disclosure, thefirst tank-side pipe passage part which is connected to the uppersurface of the fuel tank and the second tank-side pipe passage partwhich extends toward the other side of the fuel tank from the one sideof the fuel tank in the vehicle widthwise direction and is communicablyconnected with the first tank-side pipe passage part constitute a partof the charge pipe passage and are fixed to the upper surface of thefuel tank. Accordingly, even when the first tank-side pipe passage partis connected to the fuel tank at either one of positions in the vehiclewidthwise direction, it is possible to suppress an amount of fuel whichflows out from the fuel tank toward the fuel absorption means sidethrough the charge pipe passage when the motorcycle falls. Further, atleast the part of the charge pipe passage is mounted on the fuel tank inadvance and hence, the structure can contribute to the enhancement ofassembling property.

According to the second technical feature of the present disclosure, thefirst tank-side pipe passage part which extends toward the one side ofthe fuel tank from the connection part thereof connected to the uppersurface of the fuel tank in the vehicle widthwise direction is connectedto the second tank-side pipe passage part and hence, the flowout of fuelwhen the motorcycle falls can be effectively suppressed.

According to the third technical feature of the present disclosure, thefuel filling port is formed in the upper surface of the fuel tank on theone side in the vehicle widthwise direction, and the first tank-sidepipe passage part and the second tank-side pipe passage part areconnected to each other in a state where the first tank-side pipepassage part and the second tank-side pipe passage part surround theperiphery of the fuel filling port. Accordingly, the part of the firsttank-side pipe passage part and the part of the second tank-side pipepassage part can be arranged with large curvatures respectively bymaking use of a dead space around the fuel filling port thus easing thearrangement of the first tank-side pipe passage part and the secondtank-side pipe passage part.

According to the fourth technical feature of the present disclosure, thepart of the first tank-side pipe passage part and the part of the secondtank-side pipe passage part pass below the tray which is arranged aroundthe fuel filling port. Accordingly, even when the part of the firsttank-side pipe passage part and the part of the second tank-side pipepassage part are arranged so as to surround the fuel filling port, anarea of the tray can be increased.

According to the fifth technical feature of the present disclosure, thethird tank-side pipe passage part which is connected to the secondtank-side pipe passage part on the other side in the vehicle widthwisedirection has the highest part arranged at the highest position of thecharge pipe passage at the intermediated position thereof. Accordingly,the flowout of fuel when the motorcycle falls can be more effectivelysuppressed.

According to the sixth technical feature of the present disclosure, thepart of the third tank-side pipe passage part which includes at leastthe highest part is formed of the elastic tube, and the highest part ofthe elastic tube is supported on the highest part support part mountedon the fuel tank from below. Accordingly, the degree of freedom indesign can be enhanced by determining the height of the highest partbased on the height of the highest part support part.

According to the seventh technical feature of the present disclosure,the part of the charge pipe passage ranging from the highest part to theconnection part with the fuel tank is arranged with a downward gradient.Accordingly, fuel stored in the charge pipe passage between the highestpart and the fuel tank can be easily returned to the fuel tank side.

According to the eighth technical feature of the present disclosure, thecrankcase of the engine constitutes the fuel absorption means by which afuel gas is absorbed in oil, and the first check valve which prevents abackflow of a fuel gas toward the fuel tank is interposed on the chargepipe passage downstream of the highest part. Accordingly, it is possibleto effectively prevent oil in the crankcase from flowing toward the fueltank by the use of the first check valve, and it is also possible toenhance assembling property by supporting the first check valve on thefuel tank.

According to the ninth technical feature of the present disclosure, theupper surface of the fuel tank includes the higher part in which thefuel filling port is formed and the lower part lower than the higherpart, and the first check valve is arranged on the lower part.Accordingly, it is possible to prevent the first check valve from takinga high arrangement position.

According to the tenth technical feature of the present disclosure, thelower part is formed in a downwardly inclined manner toward thecrankcase. Accordingly, it is possible to make the flow of a fuel gaswhich passes through the first check valve smooth.

According to the eleventh technical feature of the present disclosure,the branch part is formed on the charge pipe passage at the positioncloser to the fuel tank side than the first check valve, and theatmospheric air introducing pipe passage which introduces an atmosphericair to the inside of the fuel tank and on which the second check valvewhich prevents the flow of a fuel gas from the fuel tank side isinterposed is connected to the branch part. Accordingly, when thepressure inside the fuel tank becomes a negative pressure, atmosphericair is introduced into the inside of the fuel tank so as to adjust thepressure in the fuel tank to an atmospheric pressure. Further, it ispossible to prevent a fuel gas from being discharged to the outsidethrough the atmospheric air introducing pipe passage by the second checkvalve.

According to the twelfth technical feature of the present disclosure,the upper open clamper which holds the part of the elastic tube which isarranged above the fuel tank out of the elastic tube which constitutesat least the part of the charge pipe passage is mounted on the uppersurface of the fuel tank, and the tank cover which prevents the removalof the elastic tube from the upper open clamper is arranged such thatthe fuel tank is covered with the tank cover from above. Accordingly,the part of the charge pipe passage can be supported on the fuel tankwith the simple structure and hence, the assembling property can beenhanced.

Further, according to the thirteenth technical feature of the presentdisclosure, paint treatment is applied to the outer surface of the fueltank, and the metallic pipe which constitutes the part of the chargepipe passage is fastened to the fuel tank. Accordingly, compared to acase where the metallic pipe is fixed to the fuel tank by welding, it isunnecessary to apply masking to the metallic pipe and hence, a paintingcost can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages of the invention will become apparent in the followingdescription taken in conjunction with the drawings, wherein:

FIG. 1 A plan view showing a rear part of a vehicle body frame, a fueltank and an engine;

FIG. 2 A view as viewed in the direction indicated by an arrow 2 in FIG.1;

FIG. 3 A view as viewed in the direction indicated by an arrow 3 in FIG.1;

FIG. 4 A perspective view as viewed in the direction indicated by anarrow 4 in FIG. 1;

FIG. 5 A perspective view as viewed in the direction indicated by anarrow 5 in FIG. 1;

FIG. 6 A side view of a motorcycle;

FIG. 7 A view showing the motorcycle in a state where a rider's seat isomitted as viewed in the direction indicated by an arrow 7 in FIG. 6;

FIG. 8 A perspective view of a part shown in FIG. 7 as viewed from anoblique anterior angle;

FIG. 9 A cross-sectional view taken along a line 9-9 in FIG. 7;

FIG. 10 A view as viewed in the direction indicated by an arrow 10 inFIG. 1;

FIG. 11 An enlarged cross-sectional view taken along a line 11-11 inFIG. 7; and

FIG. 12 A cross-sectional view taken along a line 12-12 in FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the present disclosure is explained in conjunction withFIG. 1 to FIG. 12. In the explanation of the embodiment madehereinafter, directions such as “frontward direction” and “rearwarddirection”, and “leftward direction” and “rightward direction” followthe directions as viewed from a rider who rides on a motorcycle.Further, in the explanation made hereinafter, “ . . . ” is used foromitting the repetition of the use of the same reference symbol.

Firstly, in FIG. 1 to FIG. 5, a pair of left and right seat frames 15,15 which constitute a part of a vehicle body frame F of a scooter-typemotorcycle are formed of a pipe. The pair of left and right seat frames15, 15 include inclined parts 15 a . . . which are inclined rearwardlyand upwardly and horizontal parts 15 b . . . which extend rearwardlyfrom upper ends of the inclined parts 15 a . . . respectively, and rearends of both horizontal parts 15 b . . . are integrally connected toeach other by a connection part 16.

A front part of a power unit P is supported on the vehicle body frame Fin a vertically swingable manner by way of a link mechanism 17 belowboth seat frames 15 . . . , and a rear wheel WR which is arranged on arear right side of the power unit P is pivotally supported on a rearpart of the power unit P. Further, the power unit P is constituted of aforced air-cooled single cylinder 4-cycle engine E which generates powerfor driving the rear wheel WR and a continuously variable transmission Mwhich is arranged between the engine E and the rear wheel WR, and a rearcushion unit 18 is arranged between a connection part between theinclined part 15 a and the horizontal part 15 b of the left seat frame15 out of the both seat frames 15 . . . and a rear part of the powerunit P.

An engine body 19 of the engine E includes a crankcase 20 and a cylinderhead 22 which is arranged in front of the crankcase 20. The continuouslyvariable transmission M is housed in the inside of a transmission case23 which extends rearwardly from the engine body 19 while using a partof the crankcase 20 as a constitutional element thereof, and the rearwheel WR is pivotally supported on a rear part of the transmission case23.

A fan (not shown in the drawing) which is rotated in response to anoperation of the engine E is housed in the transmission case 23. One endportion of an intake duct 24 having a bellows shape is connected to afront part of the transmission case 23 for introducing cooling air intothe inside of the transmission case 23 using the fan, and the other endportion of the intake duct 24 is connected to a lower part of theinclined part 15 a of the left seat frame 15. That is, air from theinside of the left seat frame 15 is introduced into the inside of thetransmission case 23 as cooling air.

Most of the engine body 19 is covered with a shroud 25. The fan (notshown in the drawing) which sucks cooling air into the inside of theshroud 25 from an intake port 26 formed in a right side wall of theshroud 25 is housed in the shroud 25 in a state where the fan is drivenby the engine E.

An intake device 28 is connected to an upper side surface of thecylinder head 22 of the engine body 19. The intake device 28 includes anair cleaner 29 which is arranged on a left side of the rear wheel WR, aconnecting tube 30 which has an upstream end thereof connected to theair cleaner 29, a throttle body 31 which is connected to a downstreamend of the connecting tube 30, and an intake pipe 32 which connects thethrottle body 31 and the cylinder head 22. A fuel injection valve 33 ismounted on the intake pipe 32.

Further, an exhaust device 34 is connected to a lower side surface ofthe cylinder head 22, and the exhaust device 34 includes an exhaustmuffler 35 which is arranged on a right side of the rear wheel WR, andan exhaust pipe 36 which connects the exhaust muffler 35 and thecylinder head 22 to each other.

A first cross member 37 is provided between intermediate portions of theinclined parts 15 a . . . of the both seat frames 15 . . . whichconstitute the part of the vehicle body frame F in a state where thefirst cross member 37 straddles a front part of the engine body 19, anda second cross member 38 is provided between connection parts betweenthe inclined parts 15 a . . . and the horizontal parts 15 b . . . of theboth seat frames 15 . . . .

As shown in FIG. 6, the vehicle body frame F is covered with a vehiclebody cover 39 made of a synthetic resin, and a tandem-type rider's seat40 is arranged above a rear part of the vehicle body cover 39.

A fuel tank 42 which is arranged below the rider's seat 40 is supportedon a rear part of the vehicle body frame F in a state where the fueltank 42 is arranged between the second cross member 38 which is providedbetween both seat frames 15 . . . and the connection part 16 whichintegrally connects the rear parts of both seat frames 15 . . . to eachother. The fuel tank 42 is arranged above the power unit P.

To explain the embodiment also in conjunction with FIG. 7 to FIG. 9, thefuel tank 42 is covered with a tank cover 44 from above, and the tankcover 44 is integrally connected to a rear upper edge of asynthetic-resin-made storage box 43 which is arranged in front of thefuel tank 42 between the both seat frames 15 . . . . The tank cover 44extends rearwardly from the storage box 43 in a state where the tankcover 44 passes through a space formed between the rider's seat 40 andthe fuel tank 42. Further, the storage box 43 is formed with an openedupper end, and this upper-end opening portion of the storage box 43 isclosed by a front part of the rider's seat 40.

To focus on FIG. 9, the fuel tank 42 is formed by joining an upper tankhalf body 45 which has a box shape and opens downwardly and a lower tankhalf body 46 which has a box shape and opens upwardly to each other, anda flange part 42 a which projects outwardly is formed on a joint portionof the upper tank half body 45 and the lower tank half body 46.

A first stay 47 is fixedly mounted on a center portion of the secondcross member 38 in the vehicle widthwise direction in an upwardlyprojecting manner, and a front portion of the flange part 42 a of thefuel tank 42 is fastened to and is supported on the first stay 47.Further, second stays 48 . . . which project upwardly are fixedlymounted on rear portions of the horizontal parts 15 b . . . of the bothseat frames 15 . . . respectively, and both left and right rear portionsof the flange part 42 a of the fuel tank 42 are fastened to and aresupported on the second stays 48 . . . .

A third stay 49 which projects downwardly is fixedly mounted on thesecond cross member 38 at a portion where the first stay 47 is fixedlymounted, a fourth stay 50 which projects vertically is fixedly mountedon the connection part 16 which integrally connects the rear parts ofthe both seat frames 15 . . . to each other, and a fender 51 which isarranged between the fuel tank 42 and the rear wheel WR so as to coverthe rear wheel WR from above is supported on a lower part of the thirdstay 49 and a lower part of the fourth stay 50.

A rear cover 52 which constitutes a part of the vehicle body cover 39and is contiguously arranged with a rear part of the tank cover 44 and acarrier 53 which is arranged behind the rider's seat 40 are supported onan upper portion of the fourth stay 50 by fastening the rear cover 52and the carrier 53 together by threadedly engaging bolts 55 with nuts 54fixedly mounted on the upper portion of the fourth stay 50.

Here, projecting parts 44 a . . . which project more outwardly than therider's seat 40 are integrally formed with both sides of the tank cover44, and both side portions of the carrier 53 are formed such that theside portions of the carrier 53 are smoothly and contiguously arrangedwith the projecting parts 44 a . . . . Both projecting parts 44 a . . .and both side portions of the carrier 53 function as a grab rail which apillion who is seated on a rear part of the rider's seat 40 can grasp.

To explain the embodiment also in conjunction with FIG. 10, the rearpart of the tank cover 44 which covers the fuel tank 42 from above issupported on a fifth stay 56 which is formed into an approximatelydownwardly-opened U shape so as to straddle the rear part of the fueltank 42. Fastening plate portions 56 a . . . which sandwich both leftand right rear portions of the flange part 42 a of the fuel tank 42between the second stays 48 . . . and the fastening plate portions 56 a. . . respectively are mounted on both left and right end portions ofthe fifth stay 56. Bolts 57 penetrate the fastening plate portions 56 a. . . and the flange part 42 a . . . are threadedly engaged with weldednuts 58 which are fixedly mounted on lower surfaces of the second stays48 . . . and hence, the fastening plate portions 56 a . . . of the bothleft and right end portions of the fifth stay 56 and the both left andright rear portions of the flange part 42 a of the fuel tank 42 arefastened together to the second stays 48 . . . respectively. Further,both sides of the rear part of the tank cover 44 are fastened to thefifth stay 56 by bolts 59, 59.

Box receiving members 60, 60 are mounted on both sides of the firstcross member 37, and both sides of a front part of the storage box 43are fastened to both box receiving members 60 . . . by bolts 61, 61 in astate where a resilient member (not shown in the drawing) is interposedbetween both sides of the front part of the storage box 43 and the boxreceiving members 60 . . . .

Here, the rider's seat 40 is rotatably and pivotally supported on anupper portion of a front end of the storage box 43 in a state where therider's seat 40 is rotatable between a closed state where the rider'sseat 40 covers the storage box 43 and the tank cover 44 from above andan open state where the storage box 43 and the tank cover 44 areexposed. A seal member 62 (see FIG. 9) which is resiliently brought intocontact with an upper end of the storage box 43 in the closed state ismounted on a lower surface of the rider's seat 40.

Further, an engaging member 63 is mounted on a lower part of the rider'sseat 40 at a position corresponding to a front part of the tank cover44, and a seat locking opening part 64 into which the engaging member 63is inserted in a state where the rider's seat 40 is closed is mounted ona connection part where the storage box 43 and the tank cover 44 areconnected to each other.

Further, a seat locking stay 65 which is brought into contact with thefront part of the tank cover 44 from below is arranged at a positioncorresponding to the seat locking opening portion 64 such that the frontportion of the flange part 42 a of the fuel tank 42 is sandwichedbetween the seat locking stay 65 and the first stay 47 and hence, thefront portion of the flange part 42 a and the seat locking stay 65 arefastened together to the first stay 47 by a pair of bolts 66, 66.Further, the front part of the tank cover 44 is fastened to the seatlocking stay 65 by bolts 66, 66 which are arranged on both left andright sides of the seat locking opening portion 64.

A seat locking mechanism not shown in the drawing is provided to theseat locking stay 65, and the seat locking mechanism can change over alocked state where the seat locking mechanism is engaged with theengaging member 63 which is inserted into the seat locking openingportion 64 in a state where the rider's seat 40 is closed thus holdingthe closed state of the rider's seat 40 and an unlocked state whichallows a manipulation to open the rider's seat 40 by releasing theengagement between the seat locking mechanism and the engaging member63.

A fuel filling port 67 is formed in an upper surface of the rear part ofthe fuel tank 42 on one side in the vehicle widthwise direction, thatis, a left side in the vehicle widthwise direction in this embodiment.The fuel filling port 67 is formed of a fuel filling sleeve 68 which isfixedly mounted on the upper tank half body 45 of the fuel tank 42 in anupwardly projecting manner from the upper surface of the fuel tank 42,and the fuel filling port 67 is closed by a cap 69 in anopenable/closeable manner. Further, a tray 70 which receives fuel spiltfrom the fuel filling port 67 is arranged around the fuel filling port67, and the tray 70 is fixed to the fuel filling sleeve 68.

An upper end portion of a pump module 72 for discharging fuel in thefuel tank 42 is fastened to a center portion of the upper surface of thefront part of the fuel tank 42 in the vehicle widthwise direction by aplurality of bolts 73, 73 . . . . A fuel supply tube 74 which iscommunicably connected to the pump module 72 has a portion which extendsfrontwardly from the pump module 72 above the fuel tank 42 on a rightside in the vehicle widthwise direction, a portion which extends alongthe second cross member 38 from a right side to a left side in thevehicle widthwise direction, and a portion which extends toward the fuelinjection valve 33 from the second cross member 38 on a left side in thevehicle widthwise direction partially along the inclined part 15 a ofthe left seat frame 15, and the fuel supply tube 74 having such portionsis connected to the fuel injection valve 33. To support the fuel supplytube 74, an fuel supply tube support member 75 is mounted on the secondcross member 38, fuel supply tube support members 76, 77 are mounted onthe inclined part 15 a of the left seat frame 15, and an fuel supplytube support member 78 is mounted on an upper surface of the shroud 25in the vicinity of the fuel injection valve 33.

An opening portion 79 which allows the fuel filling port 67 formed inthe upper surface of the fuel tank 42 to face upwardly is formed in thetank cover 44, and the tray 70 is resiliently brought into contact witha lower surface of the tank cover 44 so as to close the opening portion79.

A bulging part 80 which dams up the fuel overflown to the outside of theopening portion 79 at the time of supplying fuel to the fuel fillingport 67 from above is formed on the tank cover 44 in an upwardly bulgingmanner in a state where the bulging part 80 is endlessly continued so asto surround the opening portion 79. Particularly, a rear portion 80 a ofthe bulging part 80 largely bulges more upwardly than a front portion ofthe bulging part 80, and both left and right side portions 80 b, 80 bare formed such that an upwardly bulging amount is gradually increasedas the both left and right side portions 80 b, 80 b extend from a frontside to a rear side. Further, a pair of projections 40 a . . . which areformed on a rear lower part of the rider's seat 40 are brought intocontact with an upper portion of the rear part 80 a of the bulging part80 when an occupant is seated on the rider's seat 40 so that the rearpart 80 a of the bulging part 80 receives a weight of the rider's seat40.

The upper surface of the above-mentioned fuel tank 42 includes a higherpart 81 where the fuel filling port 67 is formed and a lower part 82which is lower than the higher part 81, and the pump module 72 isarranged on the lower part 82. The lower part 82 is arranged on a frontpart of the upper surface of the fuel tank 42 in an offset manner towarda right side in the vehicle widthwise direction, and is formed in adownwardly inclined manner toward the crankcase 20 of the engine body19.

A fuel gas evaporated in the fuel tank 42 is absorbed in oil in thecrankcase 20 which constitutes a fuel absorption means, wherein thecrankcase 20 is arranged below the upper surface of the fuel tank 42such that the fuel gas is absorbed outside the fuel tank 42. The fuelgas generated in the fuel tank 42 is introduced into the crankcase 20through a charge pipe passage 84.

The charge pipe passage 84 includes a first tank-side pipe passage part84 a which is connected to the upper surface of the fuel tank 42, and asecond tank-side pipe passage part 84 b which is communicably connectedwith the first tank-side pipe passage part 84 a and extends toward theother side of the fuel tank 42 from one side of the fuel tank 42 in thevehicle widthwise direction on an end portion thereof on a fuel tank 42side. The first tank-side pipe passage part 84 a extends toward the oneside of the fuel tank 42 in the vehicle widthwise direction from aconnection part 85 connected to the upper surface of the fuel tank 42,and is communicably connected to the second tank-side pipe passage part84 b. In this embodiment, the connection part 85 connected to the uppersurface of the fuel tank 42 is arranged behind the fuel filling port 67and on a center portion of the higher part 81 of the upper surface ofthe fuel tank 42 in the vehicle widthwise direction in an offset mannerfrom the fuel filling port 67 formed in the upper surface of the fueltank 42 on a left side in the vehicle widthwise direction. The firsttank-side pipe passage part 84 a is arranged such that the firsttank-side pipe passage part 84 a extends leftwardly in the vehiclewidthwise direction from the connection part 85, and the secondtank-side pipe passage part 84 b which is connected to the firsttank-side pipe passage part 84 a is arranged such that the secondtank-side pipe passage part 84 b extends toward a right side from theleft side in the vehicle widthwise direction.

The first tank-side pipe passage part 84 a and the second tank-side pipepassage part 84 b are connected to each other such that the firsttank-side pipe passage part 84 a and the second tank-side pipe passagepart 84 b surround the periphery of the fuel filling port 67, a part ofthe first tank-side pipe passage part 84 a and a part of the secondtank-side pipe passage part 84 b are arranged so as to pass below thetray 70 which receives fuel spilled from the fuel filling port 67. APart which constitutes the portion of the first tank-side pipe passagepart 84 a and the portion of the second tank-side pipe passage part 84 band passes below the tray 70 is formed of a metallic pipe 86 which isbent so as to surround a part of the fuel filling sleeve 68. Forexample, two portions of the metallic pipe 86 are held by pipe holdingmembers 87, 87. Mounting members 88, 88 are welded to the higher part 81of the upper surface of the fuel tank 42 corresponding to the pipeholding members 87 . . . , and the pipe holding members 87 . . . aremounted on the mounting members 88 . . . by bolts 89 . . . and nuts 90 .. . . Painting treatment is applied to the fuel tank 42 including themounting members 88 . . . , and the metallic pipe 86 is fastened to thefuel tank 42 to which the painting treatment is applied.

Further, the charge pipe passage 84 includes a third tank-side pipepassage part 84 c which is connected to the second tank-side pipepassage part 84 b on the other side in the vehicle widthwise direction(right side in this embodiment), and has a highest part 91 arranged at ahighest position of the charge pipe passage 84 at an intermediatedposition thereof. The third tank-side pipe passage part 84 c is arrangedto extend frontwardly above the lower part 82 of the upper surface ofthe fuel tank 42.

A part of the third tank-side pipe passage part 84 c which includes atleast the highest part 91 is formed of an elastic tube 92, and thehighest part 91 of the elastic tube 92 is supported on a highest partsupport part 93 mounted on the fuel tank 42 from below.

To focus on FIG. 11, the highest part support part 93 is constituted ofa support plate 94 which is fixedly mounted on the upper surface of thefuel tank 42 and an upper open clamper 95 which is fixedly mounted onthe support plate 94, and the highest part 91 of the elastic tube 92 issupported on an approximately U-shaped holding part 95 a which is formedon a part of the upper open clamper 95 formed of a round rod and opensupwardly from below.

The highest part support part 93 is arranged below the right side part80 b of the bulging part 80 which is formed on the tank cover 44 so thata relatively large empty space is formed above the highest part supportpart 93. In view of the above, a rib 44 b which prevents the elastictube 92 from being upwardly removed from the upper open clamper 95 isintegrally formed on the tank cover 44 such that the rib 44 b traversesthe inside of the right side part 80 b. It is desirable that the rib 44b is arranged just above the upper open clamper 95. Although the rib 44b is arranged just above the upper open clamper 95, the rib 44 b may bearranged in a slightly offset manner in the longitudinal direction ofthe elastic tube 92 from just above the upper open clamper 95 providedthat the upward removal of the elastic tube 92 from the upper openclamper 95 can be prevented at such a position.

Further, as clearly shown in FIG. 10, a part of the charge pipe passage84 ranging from the highest part 91 to the connection part 85 with thefuel tank 42 is arranged with a downward gradient toward the connectionpart 85.

A first check valve 96 which prevents a backflow of a fuel gas toward afuel tank 42 side is interposed on a part of the third tank-side pipepassage part 84 c of the charge pipe passage 84 downstream of thehighest part 91 in a state where the first check valve 96 is supportedon the fuel tank 42. The first check valve 96 is arranged above thelower part 82 of the upper surface of the fuel tank 42.

A part of the third tank-side pipe passage part 84 c of the charge pipepassage 84 includes the elastic tube 92 which has a downstream endthereof connected to the first check valve 96 and is arranged above thefuel tank 42, and an elastic tube 97 which has an upstream end thereofconnected to the first check valve 96 and is arranged above the fueltank 42. The elastic tube 92 is held by an upper open clamper 98downstream of a portion thereof held by the upper open clamper 95, andan upstream end portion of the elastic tube 97 is held by an upper openclamper 99.

The upper open clampers 98, 99 are fixedly mounted in common on asupport plate 100 which is fixedly mounted on the upper surface of thefuel tank 42. The removal of the elastic tubes 92, 97 from the upperopen clampers 95, 98, 99 mounted on the upper surface of the fuel tank42 is prevented by the tank cover 44 which covers the fuel tank 42 fromabove.

A branch part 101 is formed on the third tank-side pipe passage part 84c of the charge pipe passage 84 at a position closer to the fuel tank 42side than the first check valve 96. An atmospheric air introducing pipepassage 102 which introduces atmospheric air to the inside of the fueltank 42 is connected to the branch part 101, and a second check valve103 which prevents the flow of a fuel gas from the fuel tank 42 side isinterposed on the atmospheric air introducing pipe passage 102. Further,as clearly shown in FIG. 10, the second check valve 103 is arranged at aposition higher than the highest part 91 of the charge pipe passage 84.

The atmospheric air introducing pipe passage 102 opens in atmosphericair below the second check valve 103. In this embodiment, theatmospheric air introducing pipe passage 102 is connected to theconnection part 16 in such a manner that the atmospheric air introducingpipe passage 102 opens in atmospheric air in the pipe-shaped connectionpart 16 which connects rear parts of the pair of left and right seatframes 15 . . . to each other.

Further, a filter 104 is interposed on the atmospheric air introducingpipe passage 102 at a position closer to an atmospheric air open side,that is, a connection part 16 side than the second check valve 103. Thefilter 104 is interposed on a portion of the atmospheric air introducingpipe passage 102 which has a downward gradient toward the atmosphericair open side, that is, the connection part 16 side.

The atmospheric air introducing pipe passage 102 includes an elastictube 105 which has one end portion thereof connected to the branch part101 and the other end portion thereof connected to the second checkvalve 103, an elastic tube 106 which has one end portion thereofconnected to the second check valve 103 and the other end thereofconnected to the filter 104, and an elastic tube 107 which has one endportion thereof connected to the filter 104 and the other end portionthereof connected to the connection part 16 of the vehicle body frame F.The elastic tube 106 is arranged in an arcuately bent shape whileconnecting the second check valve 103 and the filter 104 arranged at anoblique rearward and downward position from the second check valve 103,and a part of the elastic tube 106 and the elastic tube 107 are arrangedsuch that these parts have a downward gradient toward the connectionpart 16 while connecting the filter 104 therebetween.

The other end portion of the elastic tube 105 and one end portion of theelastic tube 106 are held by the upper open clampers 108, 109 at aposition where the second check valve 103 is sandwiched between theelastic tube 105 and the elastic tube 106. These upper open clampers108, 109 are fixedly mounted on the fifth stay 56 which constitutes apart of the vehicle body frame F so that the removal of the elastictubes 105, 106 from these upper open clampers 108, 109 can be preventedby the tank cover 44 which covers the fuel tank 42 from above.

The second check valve 104 is arranged below the rear part 80 a whichreceives a load from the rider's seat 40 out of the bulging part 80formed on the tank cover 44 which covers the fuel tank 42 from above.

The charge pipe passage 84 includes: a communication pipe passage part84 d which is connected to the third tank-side pipe passage part 84 c onthe other side in the vehicle widthwise direction (a right side in thisembodiment) and extends toward one side in the vehicle widthwisedirection (a left side in this embodiment) along the second cross member38; a first engine-side pipe passage part 84 e which is connected to thecommunication pipe passage part 84 d and is arranged above the enginebody 19 in a vertically extending manner on the one side in the vehiclewidthwise direction; a second engine-side pipe passage part 84 f whichis connected to a lower end of the first engine-side pipe passage part84 e on the one side in the vehicle widthwise direction and extends fromthe one side to the other side in the vehicle widthwise direction abovethe engine body 19; and a third engine-side pipe passage part 84 g whichis connected to the second engine-side pipe passage part 84 f on theother side in the vehicle widthwise direction and is connected to theengine body 19.

In this embodiment, the communication pipe passage part 84 d isconnected to the third tank-side pipe passage part 84 c on the rightside in the vehicle widthwise direction and extends leftwardly in thevehicle widthwise direction along the second cross member 38. Thecommunication pipe passage part 84 d is connected to an upper end of thefirst engine-side pipe passage part 84 e on the left side in the vehiclewidthwise direction and extends rightwardly in the vehicle widthwisedirection along the second cross member 38 and is connected to the fueltank 42 through the third, the second and the first tank-side pipepassage parts 84 c, 84 b, 84 a. The first engine-side pipe passage part84 e extends in the vertical direction on the left side in the vehiclewidthwise direction, the second engine-side pipe passage part 84 f isarranged in an extending manner from the left side to the right side inthe vehicle widthwise direction above the engine body 19, and the thirdengine-side pipe passage part 84 g is connected to the crankcase 20 ofthe engine body 19 on the right side in the vehicle widthwise direction.

A frame-side support part 110 which supports an intermediate part of thefirst engine-side pipe passage part 84 e is mounted on the vehicle bodyframe F, and on an upper surface of the shroud 25 of the engine E, anengine-side support part 111 which supports an intermediate part of thesecond engine-side pipe passage part 84 f is mounted. The engine-sidesupport part 111 is mounted on the upper surface of the shroud 25together with the fuel supply tube support member 77 by bolts 112.

The engine-side support part 111 is arranged at a position closer to oneside in the vehicle widthwise direction (left side in this embodiment)than the intake device 28 as viewed in a plan view, and the frame-sidesupport part 110 is arranged at an oblique rearward and upward positionfrom the engine-side support part 111, and is mounted on the inclinedpart 15 a of the seat frame 15 on the one side in the vehicle widthwisedirection (left side in this embodiment) out of the both seat frames 15. . . .

Further, at least a part of the charge pipe passage 84 between theengine-side support part 111 and the frame-side support part 110 isformed of the elastic tube 97. In this embodiment, the elastic tube 97which forms a part of the third tank-side pipe passage part 84 c and hasone end portion thereof connected to the first check valve 96constitutes the whole communication pipe passage part 84 d, the wholefirst engine-side pipe passage part 84 e, the whole second engine-sidepipe passage part 84 f and a part of the third engine-side pipe passagepart 84 g.

Further, as shown in FIG. 1, the second engine-side pipe passage part 84f is arranged so as to pass below the connecting tube 30 and thethrottle body 31 of the intake device 28.

As shown in FIG. 12, the third engine-side pipe passage part 84 g isconnected to the crankcase 20 in such a manner that the thirdengine-side pipe passage part 84 g is arranged adjacent to, inside inthe vehicle widthwise direction, a fuel supply pipe 116 which isarranged on a right side part of the crankcase 20 for supplying oil tothe inside of the crankcase 20 of the engine body 19, extends obliquelyin the upward direction, and has an upper end portion thereof closed bya cap 115. The third engine-side pipe passage part 84 g is constitutedof a part of the elastic tube 97, and a metallic tubular body 117 whichhas an upper end portion thereof connected to the elastic tube 97 and isfixedly mounted on the crankcase 20. The other end of the tubular body117 opens in the inside of the crankcase 20 below an oil surface L ofoil in the crankcase 20. Accordingly, a fuel gas which is evaporated inthe fuel tank 42 and is introduced through the charge pipe passage 84 isabsorbed by oil in the crankcase 20.

Next, the manner of operation of this embodiment is explained. Thecharge pipe passage 84 which introduces a fuel gas evaporated in thefuel tank 42 toward the crankcase 20 which constitutes the fuelabsorption means includes the first tank-side pipe passage part 84 awhich is connected to the upper surface of the fuel tank 42 and thesecond tank-side pipe passage part 84 b which is communicably connectedwith the first tank-side pipe passage part 84 a and extends toward theother side (right side in this embodiment) of the fuel tank 42 from oneside (left side in this embodiment) of the fuel tank 42 in the vehiclewidthwise direction on the end portion thereof on the fuel tank 42 side.The first tank-side pipe passage part 84 a and the second tank-side pipepassage part 84 b are fixed to the upper surface of the fuel tank 42.Accordingly, even when the first tank-side pipe passage part 84 a isconnected to the fuel tank 42 at either one of positions in the vehiclewidthwise direction, it is possible to suppress an amount of fuel whichflows out from the fuel tank 42 toward the crankcase 20 through thecharge pipe passage 84 when the motorcycle falls. Further, at least thepart of the charge pipe passage 84 can be mounted on the fuel tank 42 inadvance and hence, the structure can contribute to the enhancement ofassembling property.

The first tank-side pipe passage part 84 a extends toward one side (leftside in this embodiment) of the fuel tank 42 from the connection part 85connected to the upper surface of the fuel tank 42 in the vehiclewidthwise direction, and is connected to the second tank-side pipepassage part 84 b. Accordingly, the flowout of fuel when the motorcyclefalls can be effectively suppressed.

The fuel filling port 67 is formed in the upper surface of the fuel tank42 on one side in the vehicle widthwise direction (left side in thisembodiment), and the first tank-side pipe passage part 84 a which isconnected to the upper surface of the fuel tank 42 at a position offsetfrom the fuel filling port 67 and the second tank-side pipe passage part84 b are connected to each other in a state where the first tank-sidepipe passage part 84 a and the second tank-side pipe passage part 84 bsurround the periphery of the fuel filling port 67. Accordingly, thepart of the first tank-side pipe passage part 84 a and the part of thesecond tank-side pipe passage part 84 b can be arranged with largecurvatures respectively by making use of a dead space around the fuelfilling port 67 thus easing the arrangement of the first tank-side pipepassage part 84 a and the second tank-side pipe passage part 84 b.

The tray 70 which receives fuel spilt from the fuel filling port 67 isarranged around the fuel filling port 67, and the part of the firsttank-side pipe passage part 84 a and the part of the second tank-sidepipe passage part 84 b are arranged to pass below the tray 70.Accordingly, even when the part of the first tank-side pipe passage part84 a and the part of the second tank-side pipe passage part 84 b arearranged so as to surround the fuel filling port 67, an area of the tray70 can be increased.

The charge pipe passage 84 is connected to the second tank-side pipepassage part 84 b on the other side in the vehicle widthwise direction(right side in this embodiment), and includes the third tank-side pipepassage part 84 c which has the highest part 91 arranged at the highestposition of the charge pipe passage 84 at the intermediated positionthereof. Accordingly, the flowout of fuel when the motorcycle falls canbe more effectively suppressed.

Further, the part of the third tank-side pipe passage part 84 c whichincludes at least the highest part 91 is formed of the elastic tube 92,and the highest part 91 of the elastic tube 92 is supported on thehighest part support part 93 mounted on the fuel tank 42 from below.Accordingly, the degree of freedom in design can be enhanced bydetermining the height of the highest part 91 based on the height of thehighest part support part 93. Further, the part of the charge pipepassage 84 ranging from the highest part 91 to the connection part 85with the fuel tank 42 is arranged with a downward gradient toward theconnection part 85 side. Accordingly, fuel stored in the charge pipepassage 84 between the highest part 91 and the fuel tank 42 can beeasily returned to the fuel tank 42 side.

The downstream end of the charge pipe passage 84 is connected to thecrankcase 20 in a state where the downstream end of the charge pipepassage 84 opens in the oil in the crankcase 20, and the first checkvalve 96 which prevents a backflow of a fuel gas toward the fuel tank 42is interposed on a portion of the charge pipe passage 84 downstream ofthe highest part 91. Accordingly, it is possible to effectively preventoil in the crankcase 20 from flowing toward the fuel tank 42 by thefirst check valve 96, and it is also possible to enhance assemblingproperty by supporting the first check valve 96 on the fuel tank 42.

The upper surface of the fuel tank 42 includes the higher part 81 inwhich the fuel filling port 67 is formed and the lower part 82 lowerthan the higher part 81, and the first check valve 96 is arranged on thelower part 82. Accordingly, it is possible to prevent the first checkvalve 96 from taking the high arrangement position. Further, the lowerpart 82 is formed in a downwardly inclined manner toward the crankcase20. Accordingly, it is possible to make the flow of a fuel gas whichpasses through the first check valve 96 smooth.

The atmospheric air introducing pipe 102 which introduces an atmosphericair to the inside of the fuel tank 42 is connected to the branch part101 which is formed on the third tank-side pipe passage part 84 c of thecharge pipe passage 84 at a position closer to the fuel tank 42 sidethan the first check valve 96, and the second check valve 103 whichprevents the flow of fuel from the fuel tank 42 side is interposed onthe atmospheric air introducing pipe 102. Accordingly, when the pressureinside the fuel tank 42 becomes a negative pressure, atmospheric air isintroduced into the inside of the fuel tank 42 so as to adjust thepressure in the fuel tank 42 to an atmospheric pressure. Further, it ispossible to prevent a fuel gas from being discharged to the outsidethrough the atmospheric air introducing pipe 102 by the second checkvalve 103.

The parts of the elastic tubes 92, 97 which constitute at least a partof the charge pipe passage 84 and are arranged above the fuel tank 42are held by the upper open clampers 95, 98, 99 which are mounted on theupper surface of the fuel tank 42, and the fuel tank 42 is covered withthe tank cover 44 which prevents the removal of the elastic tubes 92, 97from the upper open clampers 95, 98, 99. Accordingly, the part of thecharge pipe passage 84 can be supported on the fuel tank 42 with thesimple structure and hence, the assembling property can be enhanced.

Paint treatment is applied to the outer surface of the fuel tank 42, andthe metallic pipe 86 which constitutes the part of the charge pipepassage 84 is fastened to the fuel tank 42. Accordingly, compared to acase where the metallic pipe 86 is fixed to the fuel tank 42 by welding,it is unnecessary to apply masking to the metallic pipe 86 and hence, apainting cost can be reduced.

The second check valve 103 is arranged at a position higher than thehighest part 91 formed on the third tank-side pipe passage part 84 c ofthe charge pipe passage 84 and hence, the second check valve 103suppresses the inflow of fuel toward the second check valve 103 thusenhancing durability of the second check valve 103 by preventing theadhesion of fuel to the second check valve 103.

The branch part 101 is arranged on the third tank-side pipe passage part84 c at the position closer to the fuel tank 42 side than the highestpart 91. Accordingly, when fuel flown out from the fuel tank 42 flowsinto the atmospheric air introducing pipe passage 102 at the connectionpart with the charge pipe passage 84, that is, between the branch part101 and the second check valve 103 when a motorcycle falls, fuel in theatmospheric air introducing pipe passage 102 returns to a positionupstream of the highest part 91 of the charge pipe passage 84 when themotorcycle is raised after falling and hence, the flow of fuel towardthe engine body 19 can be prevented.

The atmospheric air introducing pipe passage 102 opens in atmosphericair below the second check valve 103. Accordingly, even when waterenters the inside of the atmospheric air introducing pipe passage 102through an atmospheric air open end of the atmospheric air introducingpipe passage 102, it is possible to make water which enters theatmospheric air introducing pipe passage 102 difficult to reach thesecond check valve 103. The filter 104 is interposed on the atmosphericair introducing pipe passage 102 at a position closer to the atmosphericair open side than the second check valve 103 and hence, dusts hardlyadhere to the second check valve 103. Further, the filter 104 isinterposed on a part of the atmospheric air introducing pipe passage 102which has a downward gradient toward the atmospheric air open side andhence, even when the filter 104 is wetted with water, it is possible todrain water toward the atmospheric air open end side from the filter104.

On the tank cover 44 which covers the fuel tank 42 from above andincludes the opening part 79 in which the fuel filling port 67 formed inthe upper surface of the fuel tank 42 upwardly faces, the bulging part80 which receives a load from the rider's seat 40 and dams up fueloverflown to the outside of the opening part 79 at the time of fillingfuel to the fuel filling port 67 from above is formed in an upwardlybulging manner, and the second check valve 103 is arranged below thebulging part 80. Accordingly, the second check valve 103 is arranged ata high position and hence, it is possible to make water which enters theinside of the atmospheric air introducing pipe passage 102 moredifficult to reach the second check valve 103.

The charge pipe passage 84 includes: the first engine-side pipe passagepart 84 e which is arranged above the engine body 19 in a verticallyextending manner on one side in the vehicle widthwise direction (leftside in this embodiment) of the engine body 19; the second engine-sidepipe passage part 84 f which is connected to the lower end of the firstengine-side pipe passage part 84 e on the one side in the vehiclewidthwise direction and extends from the one side to the other side inthe vehicle widthwise direction (right side in this embodiment) abovethe engine body 19; and the third engine-side pipe passage part 84 gwhich is connected to the second engine-side pipe passage part 84 f onthe other side in the vehicle widthwise direction and is connected tothe engine body 19. Accordingly, it is possible to suppress the flow outof oil in the engine body 19 to the inside of the charge pipe passage 84when the motorcycle falls.

Further, the frame-side support part 110 which supports the firstengine-side pipe passage part 84 e is mounted on the vehicle body frameF, the engine-side support part 111 which supports the secondengine-side pipe passage part 84 f is mounted on the shroud 25 of theengine E, and at least a part of the charge pipe passage 84 between theengine-side support part 111 and the frame-side support part 110 isformed of the elastic tube 97 and hence, the charge pipe passage 84 canfollow the swing of the engine E.

The second engine-side pipe passage part 84 f is arranged so as to passbelow the intake device 28 which extends rearwardly from an upper sidesurface of the cylinder head 22 of the engine body 19 and hence, a partof the charge pipe passage 84 can be arranged by making use of a deadspace below the intake device 28.

The engine-side support part 111 is mounted on the engine E at aposition closer to one side in the vehicle widthwise direction than theintake device 28 as viewed in a plan view. Accordingly, a part of thecharge pipe passage 84 which passes below the intake device, that is,the second engine-side pipe passage part 84 f can be fixed such that thesecond engine-side pipe passage part 84 f does not swing relative to theengine body 19 and hence, the intake device 28 can be arranged close tothe engine body 19 while obviating the contact of the intake device 28with the charge pipe passage 84 thus contributing to making the engine Ecompact.

The vehicle body frame F includes the pair of left and right seat frames15 . . . which have the inclined parts 15 a . . . extending rearwardlyand upwardly respectively, the power unit P is swingably supported onthe vehicle body frame F below the seat frames 15 . . . , and theframe-side support part 110 is arranged at an oblique rearward andupward position from the engine-side support part 111 and is mounted onthe inclined part 15 a of the seat frame 15 on one side in the vehiclewidthwise direction (left side in this embodiment) out of both seatframes 15 . . . . Accordingly, the engine-side support part 111 and theframe-side support part 110 can be arranged in a spaced-apart mannerfrom each other in the longitudinal direction and hence, a diffractionamount of the elastic tube 97 caused by the swing of the power unit Pcan be made small.

Further, the second cross member 38 is provided between the pair of seatframes 15 . . . behind the frame-side support part 110, the fuel tank 42which is arranged behind the second cross member 38 is supported on theboth seat frames 15 . . . , and the charge pipe passage 84 includes thecommunication pipe passage part 84 d which is communicably connected tothe upper end of the first engine-side pipe passage part 84 e on oneside in the vehicle widthwise direction, extends toward the other sidein the vehicle widthwise direction along the second cross member 38, andis connected to the fuel tank 42. Accordingly, the flowout of oil intothe inside of the charge pipe passage 84 from the engine body 19 sidecan be more effectively suppressed.

Although the embodiment of the present disclosure has been explainedheretofore, the present disclosure is not limited to the above-mentionedembodiment, and various design modifications may be made withoutdeparting from the gist of the present disclosure described in Claims.

For example, the invention described in Claims 1 to 7 is also applicableto a motorcycle where a canister which constitutes the fuel absorptionmeans is arranged below the upper surface of the fuel tank 42.

Although a specific form of embodiment of the instant invention has beendescribed above and illustrated in the accompanying drawings in order tobe more clearly understood, the above description is made by way ofexample and not as a limitation to the scope of the instant invention.It is contemplated that various modifications apparent to one ofordinary skill in the art could be made without departing from the scopeof the invention which is to be determined by the following claims.

1. An evaporated fuel treatment device for a motorcycle comprising: anengine which generates power for driving a rear wheel; a fuel tank whichstores fuel to be supplied to the engine; a fuel absorption means whichis arranged outside the fuel tank and below an upper surface of the fueltank which absorbs a fuel gas evaporated in the fuel tank; and a chargepipe passage which introduces a fuel gas to the fuel absorption meansfrom the fuel tank, wherein the charge pipe passage includes a firsttank-side pipe passage part which is connected to the upper surface ofthe fuel tank, and a second tank-side pipe passage part which isconnected with the first tank-side pipe passage part and extends towardan opposite side of the fuel tank in the vehicle widthwise direction,wherein the first tank-side pipe passage part and the second tank-sidepipe passage part are fixed to the upper surface of the fuel tank. 2.The evaporated fuel treatment device for a motorcycle according to claim1, wherein the first tank-side pipe passage part extends toward the oneside of the fuel tank from a connection part connected to the uppersurface of the fuel tank in the vehicle widthwise direction, and isconnected to the second tank-side pipe passage part.
 3. The evaporatedfuel treatment device for a motorcycle according to claim 2, wherein afuel filling port is formed in the upper surface of the fuel tank on aside of the vehicle in the widthwise direction, wherein the firsttank-side pipe passage part, which is connected to the upper surface ofthe fuel tank at a position offset from the fuel filling port, and thesecond tank-side pipe passage part, are connected to each other in astate where the first tank-side pipe passage part and the secondtank-side pipe passage part surround the periphery of the fuel fillingport.
 4. The evaporated fuel treatment device for a motorcycle accordingto claim 3, wherein a tray which receives fuel spilt from the fuelfilling port is arranged around the fuel filling port, and a part of thefirst tank-side pipe passage part and a part of the second tank-sidepipe passage part are arranged to pass below the tray.
 5. The evaporatedfuel treatment device for a motorcycle according to claim 1, wherein thecharge pipe passage includes a third tank-side pipe passage part whichis connected to the second tank-side pipe passage part on a side of thefuel tank in the vehicle widthwise direction and has a highest partarranged at a highest position of the charge pipe passage at anintermediated position thereof.
 6. The evaporated fuel treatment devicefor a motorcycle according to claim 5, wherein a part of the thirdtank-side pipe passage part which includes at least the highest part, isformed of an elastic tube, and the highest part of the elastic tube issupported on a highest part support part mounted on the fuel tank frombelow.
 7. The evaporated fuel treatment device for a motorcycleaccording to claim 5, wherein a part of the charge pipe passage rangingfrom the highest part to the connection part connected to the fuel tankis arranged with a downward gradient toward the connection part.
 8. Theevaporated fuel treatment device for a motorcycle according claim 5,wherein the fuel absorption means is a crankcase which stores oil forabsorbing the fuel gas and constitutes a part of the engine, wherein adownstream end of the charge pipe passage is connected to the crankcasein a state where the downstream end of the charge pipe passage opens inthe oil, and wherein a first check valve which prevents a backflow of afuel gas toward the fuel tank is interposed on the charge pipe passagedownstream of the highest part in a state where the first check valve issupported on the fuel tank.
 9. The evaporated fuel treatment device fora motorcycle according to claim 8, wherein the upper surface of the fueltank includes a higher part in which the fuel filling port is formed anda lower part lower than the higher part, and wherein the first checkvalve is arranged on the lower part.
 10. The evaporated fuel treatmentdevice for a motorcycle according to claim 9, wherein the lower part isformed in a downwardly inclined manner toward a crankcase side.
 11. Theevaporated fuel treatment device for a motorcycle according to claim 8,wherein an atmospheric air introducing pipe passage which introducesatmospheric air to the inside of the fuel tank is connected to a branchpart which is formed on the charge pipe passage at a position closer toa fuel tank side than the first check valve, and wherein a second checkvalve which prevents the flow of fuel from the fuel tank side isinterposed on the atmospheric air introducing pipe passage.
 12. Theevaporated fuel treatment device for a motorcycle according to claim 1,wherein a part of an elastic tube which constitutes at least a part ofthe charge pipe passage and is arranged above the fuel tank is held byan upper open clamper which is mounted on the upper surface of the fueltank, and wherein the fuel tank is covered with a tank cover whichprevents the removal of the elastic tube from the upper open clamperfrom above.
 13. The evaporated fuel treatment device for a motorcycleaccording to claim 1, wherein paint treatment is applied to an outersurface of the fuel tank, and a metallic pipe which constitutes a partof the charge pipe passage is fastened to the fuel tank.